2013 Day2P27 Life of Binaries: Pop Quiz: ELF vs PE Section Header Similarities And Differences
Have you ever wondered what happens when a C program is compiled and executed on a system? This three-day class by Xeno Kovah will investigate the life of a binary from birth as C source code to death as a process running in memory being terminated.
Topics will include but are not limited to:
*Scanning and tokenizing source code.
*Parsing a grammar and outputting assembly code.
*Different targets for x86 assembly object files generation. (E.g. relocatable vs. position independent code).
*Linking object files together to create a well-formed binary.
*Detailed description of the Windows PE binary format.
*How Windows loads a binary into memory and links it on the fly before executing it.
*Detailed description of the Unix/Linux/BSD ELF binary format.
Along the way we will discuss the relevance of security at different stages of a binary's life, from how viruses *really* work, to the way which malware "packers" duplicate OS process execution functionality, to the benefit of a security-enhanced OS loader which implements address space layout randomization (ASLR).
Lab work will include:
*Using the new "Binary Scavenger Hunt
" tool which creates randomized PE binaries and asks randomized questions about the material you just learned!
*Manipulating compiler options to change the type of assembly which is output
*Manipulating linker options to change the structure of binary formats
*Reading and understanding PE files with PEView
*Using WinDbg to watch the loader resolve imports in an executable
*Using Thread Local Storage (TLS) to obfuscate control flow and serve as a basic anti-debug mechanism
*Creating a simple example virus for PE
*Analyze the changes made to the binary format when a file is packed with UPX
*Using the rootkit technique of Import Address Table (IAT) hooking to subvert the integrity of a program's calls to external libraries, allowing processes to be hidden.
The prerequisites for this class are a basic understanding of C programming and compilation. This class is recommended for a later class on Rootkits
) as we talk about IAT Hooking, and required for a later class on malware analysis.